This is because by default the paramater for post_type is post.
To include all the post type add the below to you arguements
$args = array( 'numberposts' => 5, 'post_type' => 'any' );
The above will include all the post_types including pages and custom post types and if you would to include specific post types use an array like
$args = array( 'numberposts' => 5, 'post_type' => array( 'post', 'movie', 'book' ) );
For more details check the codex